I thought I would share my storage solution. I found this old box in a storage clean-out and thought it was cool:
So I made dividers using a long rectangle of wood that I cut so that I could cross-hatch the interior. It fits three rows of cards perfectly. This is currently storing Dark Ages, Intrigue, and Prosperity. There's plenty of room for another set or two, especially if I leave out the randomizers and mats (no great loss).
I was going to make these cool sleeves for each set of 10 from large index cards, but it would have taken a bunch of time that I didn't have, so I just went with the fold under index card method.
I used little hooks and rubber bands to store the rules in the lid.
Not as fancy as some others, but I'm pleased with it.
